In recent years, with an object of shortening processes related to mounting methods of semiconductor chips, the use of pre-applied underfill film (PUF) wherein an underfill film is applied to electrodes of an integrated circuit (IC) has been investigated.
Mounting methods using this pre-applied underfill film are, for example, performed in the following manner (For example, refer to PTL 1).
Step A: An underfill film is applied to a wafer and the wafer is diced to obtain a semiconductor chip(s).
Step B: The semiconductor chip is aligned on the substrate.
Step C: The semiconductor chip and substrate are crimped together by using a high temperature and a high pressure, electrical conduction is ensured using metallic bonding of solder bumps, and the semiconductor chip is bonded to the substrate by curing of the underfill film.
Because conventional underfill films are formed using a single curing agent, fine control of behavior thereof from a molten state to a cured state is difficult and adaptation of behavior thereof from molten state to cured state to conditions of actual flip-chip bonding has not been possible. As a result, voids are generated and, moreover, bonding defects such as resin entering between bumps occur.